Will be disappointing if we can't sign him as he does seem to be a near perfect fit, but understand that PL sides like Brighton are always going to look to rinse us whenever they think there is the opportunity.
One factor to consider is that all PL clubs face demands of massively inflated fees from a potential selling club for players they target, even when it's between other PL clubs.
This appears especially true when the targeted player has immense value to the buying club, and the sale likely to have a massive impact on the selling club's goals. With Cucurella and our LB needs it's not hard to see its role here.
I believe a similar logic can be applied to our attempts to buy Kane last summer, Koulibaly, as well as with Grealish who Villa would have asked for even more outside of the release clause, when we signed Walker, and possibly when we signed Sterling.
Fan resentment from the selling club is also a key factor for the selling club. Laporte and Rodri would have sold for FAR more if there wasn't a release clause. We know both Spanish clubs were angry that we got them for too low. How we landed Rodri actually shouldn't be ignored as impacting the vitriol we received from Atleti fans in CL last season. We also know that Villa fans surely remember how we got Delph so this is also where some of their resentment came from.
This pattern however tends to take place more with mid and lower table clubs rather than the likes of Spurs. Sure, we know Levy is who he is, but one should consider that he also faces some similar pressures as Brighton but in a different form due to importance of his probable goals: consistent top 4, knockouts of CL, challenge for best of rest of top 8 outside City & Liverpool, recoup losses from new stadium/COVID.
The financial dynamics of football today means that when a rich club attempts to buy a less rich club's key asset/player to fill a hard to find identified need in the squad, an inflated fee will be quoted to the buyer.
The buyer today is also more common to be a PL club. However, if the feeder club that sold this player is a PL club they will ALSO then be later quoted inflated fees for nearafter targets they hope to buy from other clubs that follow the sale, especially if the player is from the PL or UEFA clubs when they look to invest in player buys to replace or improve the squad. (i.e. Torres to Chelsea, Bale to RM and Neymar to PSG)
So, if Brighton sell for a lower fee, they have less flexibility to find players as a replacement -- whom are unlikely to possess the same quality that's lost -- AND still desire to the remaining cash to invest or stuff the pockets of the owner to incentivise their willingness to sell to a club.
The owner also faces pressure from their own fans who we all know (see Villa and Spurs supporters last summer) would certainly rather see us fail than help solidify success; even if the owner doesn't feel actually share the fans' view if you ask them privately, as City's success helps bring immense cash to PL clubs.
Levy didn't do so great with Spurs when he invested from the sale of Bale, so I think that played a role in his thinking about what it would take to sell Kane.
Since Cucurella has a long contract and he like Kane doesn't seem like a bellend personality that means Brighton are in control.